Concrete septic tank



21o-532.2 SR 7 1 XR 2,440,762 g l im? 'uz ig May 4, 1948- P. N. srrToN 2,440,752

CONCRETE SEPTIC TANK Filed Jan. l, 1945 2 Sheets-SheerI 1 May 4, 1948. P. N. SITTON 2,440,762

CONCRETE SEPTIC TANK Filed Jan. 1, 1945 2 Sheets-Sheet 2 INVENTOR nml? N. SITTON,

ATTORN EYS Patented May 4, 1948 UNITED STATES PATENT OF'FICE CONCRETE SEPTIC TANK Philip N. Sitton, Dayton, Ohio Application January 1, 1945, Serial No. 570,858

y (ci. 21o-s) 1 Claim.

1. This invention relates to septic tanks. An object of the invention is to provide a cast concrete septic tank of an improved design.

Another object of the invention is to provide a cast concrete septic tank that can be cast in sections and assembled at the site of installation.

Still another object of the invention is to provide a cast concrete septic tank that is in the shape of a polygon having generally a conic section.

Still another object of the invention is to provide a cast concrete septic tank having a. contour adapted to more favorably withstand ground pressure and changes in the ground pressure due to various changing conditions of the ground.

Still another object of the invention is to pro1 vide a cast concrete septic tank having concrete battles that are suspended in position within the septic tank from the sidewalls of the tank.

Further objects and advantages will become apparent from the drawings and the following description:

In the drawings:

Figure 1 is a perspective elevational view of a concrete septic tank constructed in accordance with this invention.

Figure 2 is a plan view of the septic tank illustrated in Figure 1. but having the top cover removed therefrom.

Figure 3 is a vertical cross-sectional view taken along line 3-3 of Figure 2.

Figure 4 is a perspective view of a portion of the septic tank illustrating the manner in which the inlet baffle is suspended from the sidewalls of the tank.

`Figure 5 is a. perspective view oi' a portion of the tank illustrating the manner in which the outlet baille is supported adjacent the outlet opening by the sidewalls of the tank.

In this invention the septic tank IU consists of three principal sections II, I2 and I3. Each section II, I2 and I3 has the same general contour of the vertical sidewall illustrated in Figure 2, which may be referred to as a polygon having generally a conic section. It will be noted that the wall section is composed of a plurality of straight sidewall portions or chordal sections that fOlm the polygon shape of the sections II. I2 and I 3. the reasons for which will be more fully described hereinafter.

The tank III has a base Il upon which the section I3 is placed, the section I2 then being placed upon the section I3. The two sidewall sections I2 and I3 are identical in their construction, and

2 give suicient height tothe septic tank I0 for providing the desired capacity.

The section II of the septic tank I0 is placed upon the section I 2, and is provided with an inlet opening I5 and an outlet opening I 6. In so far as the cross-sectional shape of the section II is concerned. it is identical with sections I2 and I3 so that in describing the section II, that also incorporates other features. sections I2 and I3 will be covered sufliciently.

The :wall section II of the septic tank I0 consists oi' a plurality of straight sidewall portions or chordal sections I1 that are contiguous with one another to form a unit structure. These sidewall portions or chordal sections I'l are arranged generally as a conic section. such as an ellipse, but in the form of a polygon in view of the manyl straight sides of the wall section.

The contour of the wall section I I. which is also the contour of the wall sections I2 and I3, has been found to be especially satisfactory' in supporting ground pressure applied against the sidewalls of the septic tank Il. When a septic tank is installed underground. the ground applies considerable pressure upon the walls of the septic tan k. and which pressure shifts from time to time due to varying conditions of the ground such as its water content or freezing and thawing conditions. When the septic tank is constructed'in the form of a. polygon having generally a conic section. the ground pressure is applied over a substantial area of any one of the sections of the polygon and normal to the face of the polygon. The ground pressure thereby tends to move the particularface of the polygon inwardly toward the center of the septic tank. but due to the invisible lines of separation between the sections of the polygon, the force moving the section of the polygon inwardly tends to spread the rest of the wall section so that the force is applied to the remaining wall section normal to the face o! the section of the polygon to which the ground force is applied. The force of the ground force is therefore distributed annuiarlv around the wall section of the septic tank. It has been found that the distribution of torce obtained by the Q u... ms... Y..

pressure of which the septic tank is capable of withstanding. This is in contra-distinction to the distribution of the ground pressure as obtained by the construction of the septic tank of this invention.

As noted in Figure 2, the shape of the septic tank is generally in the form oi an ellipse, in the nature of a polygon, so that the inlet opening i5 is positioned a substantial distance from the outlet opening I 6 thereby giving the incoming waste matter a relatively large distance to travel to the outlet opening I6 and permitting settling of the waste matter in the tank. This arrangement is superior to a circular tank of equal 'capacity because of the increased iiow travel distance between the inlet and outlet openings, the flow of material taking the shortest path between the inlet and outlet in any septic tank.

The sections II, I2 and I3.of the septic tank tending around the wall of the section adjacent the top andbottom edges thereof. These reinforcing rods are preferably shaped to the contour of the wall section to provide a continuous reinforcement annularly around the Wall section.

The wall sections II. I2 and I3 of the septic tank I form the sidewall 2U of the tank I0.

A baille plate 2l is provided between opposite sidewalls of the tank ID adjacent the inlet opening I to deflect incoming matter to the bottom of the septic tank I0. This baie 2| is constructed of concrete and is provided with the ears 22 that rest within the recesses 23 formed in opposite sidewalls of the section II of the tank Ill. Suitable grouting' 24 may seal between the edge of the baie 2| and the sidewall portions or chordal section of the section II when the baiiie is installed in position in the tank. An arcuatelyshaped baiile 25 is provided adjacent the outlet opening I6 to prevent a direct now of material from the inlet into the outlet of the tank. This baille 25 is similarly suspended from the sidewall portions or chordal section of the section Il by means of the ears 26 in the upper edges thereof that are placed within the recesses 21 provided in the wall of the section II.

A top cover is provided for the tank I0 and consists of a. plurality of individual ilat sections 30 that are provided with a lap joint connection 3|. The top sections 30 are provided with hooks 32 that may be used 1'o`r placing the sections in place upon the top edge of the wall section II to close the septic tank I0.

From the foregoing description, it will be apparent that the septic tank of this invention is relatively easy to install because it is made in sections that are placed directly one upon the While the device of this invention disclosed and described herein constitutes a. preferred form of the invention, yet it will be imderstood that it is capable of mechanical alteration without departing from the spirit ot the invention, and that all modiiications that fall within the scope of the appended claims are intended to be included herein. i

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

A septic tank comprising, a. bottom wall, side wall means forming a generally elliptical hollow body with a length substantially twice that of the width thereof and comprising a plurality of joined flat chordal sections, the said side Wall means cooperating with said bottom wall to form a tank, inlet and outlet openings in said side wall adjacent the upper edge thereof and positioned in substantially the end extremities of the elliptical body, baffle means extending transversely across said elliptical body adjacent said inlet opening and forming with said side wall means a. chamber expanding outwardly in the direction of flow of material into the septic tank, baille means adjacent said outlet opening, and a. cover for closing the tank formed by said side walls and bottom wall, said septic tank having inner walls which are entirely unobstructed except for said baiile means at the ends of the tank, the angles of juncture of the inner walls of the chordal sections forming corners whose angles increase from each end of the tank toward the center thereof, and the angles o! the inner walls made by the chords adjacent the center being slightly less than the opposite ends of each of said bailies being anchored into the sides of a pair of opposite confronting chordal sections.

PHILIP N. SII'ION.

le of this patent:

UNITED STATES PATENTS Number Name Date 1,224,913 Ferguson May 8, 1917 1,334,192 Thomas et al Mar. 16, 1920 1,557,523 Hahn Oct. 13, 1925 1,574,603 Burtis Feb. 23, 1926 1,634,871 Hepler July'5, 1927 1,677,626 Frappy July 17, 1928 1,695,781 Otls Dec. 18, 1928 -1,742,911 Gutman et al. Jan. 7, 1930 1,877,507 Hendricks Sept. 13, 1932 2,086,154 Boggs July 6, 1937 2,279,813 Bent Apr. 14, 1942 2,378,616 Burgett June 19, 1945 FOREIGN PATENTS Number Country Date 43,755 Norway Feb. 21, 1927 306,192 Germany June 22, 1918 524,418 `1' Great Britain Aug. 6, 1940 645,510 France June 27, 1928 

